[Pilot-scale study on treatment of municipal sewage by moving-bed biofilm reactor with the hydrophobically modified polyurethane cubes as biofilm carriers].

The carrier is the key influencers in moving bed biofilm reactor( MBBR), in this paper, a pilot scale apparatus was set up for treating municipal wastewater using modified cubic polyurethane carriers. For MBBR, the capacity of 3-3.5 t x d(-1), hydraulic residence time of 7-8 h, under the condition of continuous feed water (COD:140-280 mg x L(-1), NH4+ -N:30-50 mg x L(-1), TN: 45-65 mg x L(-1), TP:2.5-4.0 mg x L(-1)), the speed of biofilm formation and removal effects of COD, nitrogen and phosphorus were studied. After 140 days, the results showed that the formation of biofilm on the carrier was very quickly under 24-28 degrees C, and obtained stable treatment effect about 6 days. The COD, NH4+ -N, TN, TP average removal rates were 70%, 97%, 70%, 39%, respectively. As the temperature gradually decreased to about 12 degrees C, a high NH4+ -N removal rate (97%) could still be maintained, which indicating that the modified carrier can be achieved a high nitrification rate at low temperature.

[Effects of gamma linolenic acid on atherosclerosis induced by cholesterol-rich diet in rats].

OBJECTIVE: To study the effect of gamma linolenic acid (GLA) on atherogenesis in rats. METHOD: Sixty healthy male rats were randomly divided into 6 groups: normal contro 1, fed by normal feed; atherogenesis mode 1, fed by high lipid diet; positive control group 0.9 mg x kg(-1) x d(-1) of lovastatin and group IV 250 mg x kg(-1) x d(-1) duoxikang; high dose of 375 mg x kg(-1) x d(-1) GLA; low dose of 187.5 mg x kg(-1) x d(-1) GLA. After the model group received atherogenic diet for six weeks, serum triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) were detected by enzyme method to confirm the formation of atherogenic. After fed for another five weeks, morphologic atherosclerosis of aorta in rats was observed by HE staining methods. The blood samples were collected and serum TC, TG, HDL-C, LDL-C, T-AOC, HL, LPL, NO, NOS, MDA and GSH were determined. RESULT: GLA attenuated the formation of atherosclerotic plaques, inhibited the level of serum TC, TG, MDA, OX-LDL, NO, NOS, HL, LPL and LDL-C and increased the level of T-AOC. CONCLUSION: GLA might significantly attenuate the development of atherosclerosis in rats fed with high lipid diet through improving the antioxidation capacity of the body.